


Gooey

by Frikkstikk



Category: Undertale (Video Game)
Genre: M/M, Plot What Plot/Porn Without Plot
Language: English
Status: Completed
Published: 2015-11-20
Updated: 2015-11-20
Packaged: 2018-05-02 11:52:28
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,572
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5247281
Author URL: https://archiveofourown.org/users/Frikkstikk/pseuds/Frikkstikk
Summary: <blockquote class="userstuff">
              <p>As per your requests, smut. Weird monster smut. Kind of a spinoff of my other fic.</p>
            </blockquote>





	Gooey

**Author's Note:**

  * Inspired by [Virus](https://archiveofourown.org/works/5159489) by [Frikkstikk](https://archiveofourown.org/users/Frikkstikk/pseuds/Frikkstikk). 



> None of them have genitalia. Time to go spelunking through the internet for ideas.

"I dunno about this, Metta, Alphys said you needed to relax. How is this relaxing?" Sans donned his usual grin and stared at the robot on his couch.

Mettaton uttered a short grunt as Sans straddled him. "I'll relax when we're done. If you do a good job, that is," he winked.

"Right, right," Sans nodded. "Any reason why you chose the couch?"

"Your room is a mess and so is your bed." Mettaton cocked his head to the side and smirked, "Or would you prefer doing me on Papyrus's bed?"

"Couch's fine," Sans replied hastily. "What if Papyrus comes home?" Sans looked towards the door. It wasn't far from the couch.

"He'll probably yell at us and tell us to take it elsewhere. But the threat of being caught is thrilling all the same, isn't it, darling?" Mettaton trailed a finger down Sans's sternum.

Sans shuddered. He then lifted his hands and hovered them over the robot. "How do I..." Sans looked confused. He tapped on Mettaton's core-casing for help.

A sinful grin spread across Mettaton's face, "So eager, aren't we?" He reached down and removed the clear case over his heart-shaped core. "Have at it, but be gentle," he winked and stuck his tongue out.

Sans huffed out a chuckle and scooted up Mettaton's body for a better reach. He gently began tracing the outside of the core with a single finger. Mettaton let out an excited yelp.

Almost instantly, Sans felt the core begin to secrete a pinkish, viscid liquid. He pulled his hand back and felt the substance between his index finger and thumb. Cautiously, curiously, he brought it up to his mouth and touched it to his tongue. It tasted like goddamn cherries.

Sans glanced at Mettaton's expression. Mettaton stared at him through half-lidded eyes with a smirk that could make his fans swoon. Sans felt his ribs tingle a bit. The tingling quickly changed into a quite pleasurable sensation. Wait, what?

Sans looked down at himself. Mettaton had his overzealous hands up his shirt and was rubbing the inside of his ribs. Sans sucked in a shaky breath. He wasn't going to last very long if Mettaton kept that up. "Hands to yourself, prettyboy," Sans grabbed Mettaton's wrists.

"Oh my~" Mettaton purred.

Sans snickered deviously, "Looks like I've got the _upper hand_."

"Get the fuck off," Mettaton attempted to kick the skeleton off of him, but Sans was sitting too high up and Mettaton ended up nudging him closer.

Sans was actually too short to pin Mettaton's hands a successful distance behind his head, so he settled for keeping the robot's wrists in his grasp. Now he could focus on the task at _hand._ He ran his thumb over the gelatinous surface of the core, eliciting a sensual moan from Mettaton, "More, darling."

Sans gladly complied and pressed his thumb harder against the heart. Sparks of electricity danced around his joints, sending shivers down his spine.

"That's delicious! Keep going, Sansy!" Mettaton urged him to go further.

Sans cupped the core with his hand and gave it a good squeeze.

Mettaton gasped and let out a loud groan, "Oh _yes!!!_ " 

Sans felt as though Mettaton wouldn't distract him any more, so he released the robot's wrists.

He was incorrect in his assumptions. Mettaton lifted the skeleman off of his lap for a moment. He spread his legs and put Sans on the couch between them. "This makes more sense, doesn't it?" Mettaton bent his knees and shoved Sans forward with his heels.

"Whatever turns you on," Sans shrugged, he wasn't sure if that was a pun but it worked both ways. He decided to get back to work and shoved his hands into the core's container, covering them with the sticky pink goo. Sans played by ear, meaning that his only point of reference of how well he was doing was based on how loud Mettaton whined (or how tight his legs squeezed.) Otherwise, he had no idea if Mettaton was enjoying himself, but he certainly seemed to be- what with the moaning and melodious "oh yes"s. Sans actually felt as though he was going a good job; Mettaton was a panting, mewling mess underneath him _because_ of him. Sans tested the waters even further by gripping the little heart with both hands, leaning over, and giving it a long lick up the front.

"AAH! SANS!" Mettaton's back arched off the couch and it didn't come back down for a while. Sans continued laving his tongue over the sopping wet heart. Mettaton put his hand to his mouth and bit his knuckle to quiet himself down. Sans reached up and pulled his hand away, "Nah, let me hear you." 

"Fine," Mettaton muttered indignantly. "But first, come here, darling," Mettaton beckoned him forward with a finger.

Sans blinked and paused, initially hesitant, but leaned forward anyway. Mettaton grabbed his skull and pulled him into a kiss.

Still with his fingers on the core, Sans rhythmically squeezed the poor thing- sending jolts of electricity through his bones and causing Mettaton to whimper into his mouth.

Mettaton pulled away first and went straight for Sans's neck with his mouth; biting, licking and sucking his way down to Sans's clavicle- that's about as far as Sans's shirt would stretch.

Sans seized up for a moment but he soon melted into Mettaton's touch. "Oh. Ok that's nice," he hummed.

He felt familiar hands snake up his thighs and slip under his shirt. "Metta, I- oh... ahh." A fingertip trailed down his spine from within his ribcage.

Sans gripped Mettaton's hips as the robot's hands roamed around inside his ribs. One hand slid down to his hips- _through_ his hips- and rubbed his tailbone. "S-shit, Mettaton!" he gasped.

In order to gain control of the situation, Sans gripped the core and pushed his thumb into it as hard as he could. To his surprise, it broke through. He was assaulted by volts of electricity, mild, but still exhilarating.

The sound that emanated from Mettaton was nearly enough to send Sans over the edge. He looked at the abused core and pulled his thumb out. He received a squeeze via Mettaton's legs. Sans's pupils flitted up to Mettaton's face. "C'mon, darling," Mettaton grinned, "it's showtime!"

Both of Mettaton's hands moved over to massage Sans's pelvic bone. Sans choked out an feverish moan.

Nope, nope! Sans was _not_ finishing before Mettaton. It was common courtesy! Plus, he may or may not have wanted to see Mettaton's face when he climaxed.

Sticking his thumb into the core didn't seem to damage it, so Sans had no quarrels with plunging two of his fingers into it. It squirted the pink stuff on his face. He looked Mettaton in the eye as he licked it off his cheek. He saw- and felt- Mettaton shiver. He continued to pump his fingers in and out of the core. Its container was practically filled with liquid.

Mettaton retracted his hands and held them above his head to allow Sans more freedom. "Ooh my! Don't stop! M-more! Wonderful darling, a-absolutely wonderful!!!" His hips rolled with pleasure as he encouraged his lover.

"You know, Metta, when Alphys said to take care of you I don't think she had this in mind." Sans chuckled, rubbing Mettaton's inner thigh with his free hand.

"Less talking, more fucking," Mettaton panted.

"Whatever you say, Mettababe." Sans shrugged. He decided it was time to finish this. Papyrus was bound to be home soon and they needed time to clean up this pink stuff from the couch.

Sans leaned down and touched his mouth to the heart.

Being that close to Mettaton allowed him to hear the rapid whirring coming from inside of the robot. It almost sounded like breathing.

Sans tucked his tongue under the bottom of Mettaton's core and sucked it harshly into his mouth.

That was apparently all Mettaton could take because he threw his head back, and let out a loud, lustful moan, gripping the couch with one hand and his hair in the other. Sans barely registered Mettaton's leg also shooting up for a dramatic pose. It would be hard for anyone to notice much when their mouth was being filled with pink, sparkly, _cherry flavored_ juice. Sans still couldn't get over that Mettaton came with a flavor.

"Oh god Sans, I- that was amazing!" Mettaton slumped into a very unrefined position as he basked in the excess waves of pleasure.

Sans beamed, proud of himself. "Thanks. I tried."

"Did you, um, get to..." Mettaton half-sat up.

"Nah, but I'm good," he winked. "This was about getting you to relax, right? So relax, Metta."

Mettaton smiled warmly, "Thank you."

"Yeah, no problem. How's about we get you cleaned up?" Sans patted Mettaton's knees.

Mettaton lifted his legs so Sans could get up.

Sans stood next to the couch and waited. "Well?"

"You said you wanted me to relax. So I am relaxing." Mettaton put the case back over his core, trapping in the liquid before turning on his side.

Sighing, Sans climbed back on the couch. "Screw it, we'll clean it later." He looked at Mettaton with a grin and patted his tummy, "Wanna nap?"

"Certainly." Mettaton shifted and rest his head on Sans. He was strangely soft for not actually having a belly. Mettaton didn't question it and went into sleep mode, joining Sans, who had somehow fallen asleep within seconds.

**Author's Note:**

> Don't go spelunking through the internet for ideas.  
> Sans apparently has lips/tongue. How else could he drink through a straw?  
> 


End file.
